1. Field of the Invention
This invention relates to a door closure device and more particularly to a device for delaying the closing of a door for a predetermined period as selected by the user. The door closure delay device hereof is designed for operation in conjunction with a pneumatic door closer and serves to prevent air pressurized within the housing of the door closer from escaping for a predetermined period.
2. Description of the Prior Art
Pneumatic door closers are devices which are coupled to a door and a surrounding frame to bias a door to a closing position. They also serve to retard the rate at which the door closes so as to prevent the door from "slamming " when the user releases the door to enable it to return. These door closers conventionally employ a cylindrical housing which carry a spring and a piston. The piston shifts along the interior of the housing and draws air into the housing when the door is opened and then forces the air back out when shifting back to a closed position. The rate at which the door closes is determined by the spring tension and a valve which limits the flow of air out of the housing.
Such pneumatic door closers are often provided with a stop which is slidably located along a shaft connected to the piston and the door. The stop enables the door to be held in a desired open position or can be moved along the shaft so that the door may completely close. Thus, a door can be propped open allowed to pivot between an open and closed position, but there is no provision for a delay in the amount of time the door can be held open before automatically closing by virtue of the biasing spring.
Other devices have been developed which hold a door open at a desired position. One such device is sold by Brookstone of Peterborough, N.H. which may be attached to a pneumatic closer to hold a door open at a desired position. However, this device must be manually released and does not contemplate a delay in closing.
The problem thus encountered by homeowners is the need to keep a door open for a preselected period of time in order to bring in groceries or perform other chores which occupy both hands and then have the door automatically close. Closing the door automatically saves energy costs associated with the additional heating or cooling caused by excessive flow of air through a door held open too long, or the entry into the home of insects or other pests which would otherwise be stopped by the closed door.